1. Field of the Invention
This invention relates to packaging of electronic components of a computing system and more particularly to packaging of input/output tailstock areas of large processor cards.
2. Description of Background
The industry trend has been to continuously increase the number of electronic components inside computing systems. A computing system can include a simple personal computer, a network of simple computers, or one or even a network of large computers in processing communication with one another that include one or more servers having central electronic systems (CEC). While increasing the components inside a simple computing system does create some challenges, however, such an increase create many problems in computing systems that include one or more large computers. The evolution of high end computing systems especially, including servers, have imposed particular packaging challenges with respect to a variety of problems that are seemingly isolated issues but affect one another a single assembly environment. Thermal management, mechanical integrity and electromagnetic and electrical shorts have been some of the challenging issues that have created special design concerns for the developers of such systems.
Each of these issues are further exasperated in the future by the development of next generation processors that require increased packaging density, causing more concerns especially in the area of heat dissipation. Heat dissipation if unresolved, can result in electronic and mechanical failures that will affect overall system performance. As can be easily understood, the heat dissipation increases as the packaging density increases. In larger computing systems, such as servers that include next generation processors, the problem of heat dissipation becomes of particular concern.
An increased package density has also placed increased demands on the manner the computing systems are packaged. One key problem area in large computers is how to best utilize the tailstock areas of large processing cards where traditionally input/output (I/O) areas are also located. As mentioned, thermal management in dense packages have put increasing demands on mechanical designers to utilize unique approaches to maximize cooling. Combined with the concerns in the manner that the processing cards need to be populated, thermal management has often led the designers to provide air-cooling capabilities within a predefined footprint.
A recent popular prior art approach has been to place the I/O tailstock areas in what is known as the “windward” side of the processor cards, where they are in direct contact with an air input stream. Unfortunately, in this approach, the I/O tailstock areas are governed by the amount of available air for cooling the electronic packages contained within a particular packaging assembly and depending on packaging flexibility, this approach may lead to inefficient heat dissipation.
In addition, the problem of heat dissipation is further exasperated by the recent prior art orientation of cards. Historically, the orientation of the processing cards has migrated form the more traditional in-line plugging approach to a more recent version that utilizes a blind-mate style to allow for other processing and packaging needs. The key difference between these two approaches is the fact that in the former approach, the in-line plugging connects by mating the interconnect to a card that typically lies perpendicular to the air-stream. The latter approach, however, does so in a parallel fashion which minimizes the air flow impedance.
Another development that causes additional concerns is the advancements in cable operation speed. The rise of processor and cable operation speeds, especially in the ranges exceeding 5 GHz, not only creates additional thermal management concerns but also creates issues relating to electromagnetic interference containment and mechanical support in a structural sense.
The mechanical concerns are derived from both obvious and non-obvious sources. For example, a contributing factor that may not be as obvious as the traditional mechanical support concerns stems from the fact that the increased system operating speeds have driven the necessity of implementing surface mount technology (SMT) style connectors, whose predominant mechanical support must be derived from the card's mechanical structure. This is mostly necessary in order to isolate potential damaging strains at the soldered interface.
Currently, there is no single design that can efficiently address all problems as enumerated above. Attempts to improve packaging designs to resolve of one set of the previously enumerated problems, often cause other such problems to worsen. Consequently and in light of the prior art current designs that affect overall system performance, a packaging concept is desirous that can address all such issues including but not limited to thermal management and cooling concerns, electromagnetic interface concerns and mechanical and structural support concerns in such computing system packaging but especially for those that include the next generation of blind-mated I/O card cassettes as part of their packaging and assembly.